1. Field of the Invention
The present invention relates to an installation for fighting fire, including a hydraulic accumulator which includes at least one pressure container with a space for extinguishing liquid and a space for propellant gas, a rising tube, in the pressure container, provided with a side opening and, at the lower part of the pressure container, with a feed opening for feeding extinguishing liquid into the rising tube and further to at least one nozzle.
2. The Prior Art
Such installations are known from, for example, WO 94/08659. The principal of operation is that only liquid in a mist-like, penetrating form is initially sprayed from the nozzle, after which gas is mixed into the liquid through said the openings. A reduction of the pressure in the pressure container generally produces a spray with a larger drop size out of the nozzle. Owing to the feeding of gas, the drop size of the extinguishing medium discharged from the nozzle can be reduced. These known installations largely function very well; however, in some applications, it would be desirable to be able to reduce the size of the drops discharged from the nozzle even more, after the initial spraying with a great penetration, than what has been possible with the known hydraulic accumulators and nozzles. The mixing of a large amount of gas into a small amount of liquid has been relatively difficult to achieve in practice. An enlarging of the side openings in the rising tube has not produced the desired result, but by reducing the diameter of the rising tube, it has been possible to improve the intermixing of gas somewhat. However, a reduction of the diameter of the rising tube increases the pressure losses as the flow resistance of the liquid in the rising tube increases, and sufficient liquid cannot be obtained from the pressure container upon emptying the container. By being able to produce very small droplets, the amount of extinguishing liquid that is used could be minimized and, simultaneously, if water was used as the extinguishing liquid, the water damages would be minimal. This has not always been possible to achieve to such a degree as one would have wished.